[JURIST] Canadian security authorities said Saturday that a major terrorist attack on Canadian targets had been thwarted by the arrests of twelve men and five youths [RCMP press release] in Ontario Friday. A spokesman for the Royal Canadian Mounted Police (RCMP) [official website] told a news conference [prepared text] that the suspects, charged under the terrorism provisions of Section 83 [text] of the Canadian Criminal Code, were part of a terrorist cell that had intended to bomb targets in southern Ontario and Toronto, including the headquarters of the Canadian Security Intelligence Service (CSIS) [official website]. The men are also suspected of having attended a terrorist training camp north of Toronto. Canadian Prime Minister Stephen Harper [official website] released a statement [text] saying the individuals were "allegedly intent on committing acts of terrorism against their own country and their own people." CSIS Assistant Director Luc Portelance said [CSIS statement] that those arrested "appear to have become adherents of a violent ideology inspired by Al Qaida," and described the security operation as "the largest counter-terrorism operation and arrests in Canada since the creation of the Anti-Terrorism Act and the amendment of the Criminal Code to better define terrorism."

Canada's Integrated National Security Enforcement Team (INSET) [RCMP backgrounder] and the RCMP worked together in the security operation, which also uncovered three tons of ammonium nitrate fertilizer, an ingredient commonly used in makeshift bombs. One ton of ammonium nitrate fertilizer was used in the 1995 bombing of the Murrah Federal Building in Oklahoma City that killed 168 people. A CSIS spokesman said the individuals lived in Canada and are from different backgrounds. The men were expected to appear in court later Saturday. The names of the younger suspects will not be released due to the Youth Criminal Justice Act [Canadian Department of Justice backgrounder]. Canadian Press has more.

8:15 PM ET – Fifteen of the seventeen detainees appeared in court in Brampton, Ontario, late Saturday afternoon under high security, where a justice of the peace remanded them into police custody until June 6. A number complained of the conditions in which they had been held after arrest their treatment Friday, and the Toronto Star quoted a lawyer for several as saying "I think they (the police) cast their net far too wide. We’ve been talking several lawsuits as a result of this action." The Toronto Star has more. FBI officials said Saturday that at least 3 of the men arrested in the Canadian security sweep had met with two US terror suspects from Georgia who traveled to Toronto last year but who have since been arrested by American authorities. CBC News has more.